證據理由論認為，規範理由 (normative reasons) 是一種證據，有關主體應該（或不應該）從事某個行為的命題的證據。肯恩 (Stephen Kearns) 與斯塔 (Daniel Star) 的理論，是目前最主要的證據理由論。本文的目的，在於藉由分析肯恩與斯塔理論的缺點，而發展出更合理的證據理由論。對肯恩與斯塔來說，F 是支持S 去做行為Ф的理由，當且僅當，F 是支持『S 應該去做Ф』這個命題的證據。而筆者主張，F 是支持S 去做行為Ф的理由，當且僅當，F是反對『S 應該不去做Ф』這個命題的證據。

According to reasons evidentialism, normative reasons are evidence about oughts, i.e. propositions about whether an agent ought or ought not to perform a certain action. Stephen Kearns and Danial Star’s account of reasons have been the most prominent reasons evidentialism on the table. In this paper, I will closely examine Kearns and Star’s account and articulate its problems. More importantly, learning from the drawback of Kearns and Star’s account, I propose a new account of reasons evidentialism. According to Kearns and Star, F is a reason for S to Ф if and only if F is evidence for the proposition that S ought to Ф. On my view, F is a reason for S to Ф if and only if F is evidence against the proposition that S ought not to Ф.